The present invention relates to processing grains, and more particularly to a means for expanding raw, wholeseed amaranth and extruded half products of cereal grains such as corn, wheat and oats.
Amaranth is a pseudo grain in the nature of buckwheat, used for many years in certain regions of Asia and South America. Just recently introduced into the United States, amaranth is rapidly gaining acceptance, particularly among consumers interested in health and the nutritional value of food products. In particular, amaranth is high in protein content, whereby amaranth flour can be combined with wheat flour to provide enriched flours and pancake mixes. While not a true cereal grain, amaranth is used in cereal products as well.
Another amaranth product is based upon the fact that amaranth, in the raw, wholeseed form, includes entrapped moisture. Upon a sufficiently rapid heating, the moisture expands the seed. This puffs or pops the amaranth, much in the same manner as popping corn is expanded or popped. Popped or puffed amaranth is generally spherical and about one-eighth of an inch in diameter, approximately six times (or more) the size of the raw, unpopped grain. Accordingly, puffed amaranth tends to be used as a filler to add nutrition to certain baked goods, to garnish salads, and the like. The conventional approach to popping amaranth is on a small batch basis, e.g. stove-top popping with oil, in a frying pan or the like. This must be done with care, as there is a narrow range of tolerance between insufficient heating of the amaranth to achieve popping, and excessive heating leading to charring or burning.
In recent years, concern about the greasy texture and calorie content of popcorn prepared using fats or oils, has increased the popularity of hot air corn poppers. U.S. Pat. No. 4,767,635 (Merritt et al) discloses a method for flavoring popping corn, including mixing unpopped corn with an aqueous coating mixture consisting essentially of an edible adhesive, and a flavoring such as an edible salt or other flavorant. The edible adhesive can include proteinaceous adhesives such as gelatin, alginates such as propylene glycol alginate, pectin, gums and gum arabic. The mixture is then dried to a moisture content of about 11-14 percent by weight. Thus treated, the mixture is said to retain substantially all of the added flavor upon being popped in a hot air popper.
Other foods suitable for puffing or expanding include extruded flours of amaranth and cereal grains such as corn, wheat and oats. Frequently, such products are puffed or popped by deep-fat frying, again raising concerns about the calorie content.
Alternatives to deep-fat frying are known in connection with various grain based food products. For example, U.S. Pat. No. 3,689,279 (Bedenk) discloses a high protein ready-to-eat breakfast cereal, made from a dough which is formed by combining gelatinized cereal grain (preferably corn, but also possibly wheat, oats or rice) with partially hydrolyzed soy isolate. The resultant dough is processed through an extruder into strands, which are sliced to form pellets. Following tempering to a moisture content of 12-14 percent, the pieces of dough are puffed, for example, by a process of heating under pressure followed by rapid release of the pressure.
In U.S. Pat. No. 1,946,803 (McKay), a mixture of rice and a solution of sugar, salt and water is cooked, cooled and dried, ground to small particles and tempered for uniformity in moisture content, rolled into ribbons, dried, broken into fragments and finally toasted and puffed in a rotary toaster at a temperature of 450-600 degrees F.
While the above and many other processes have proven satisfactory in connection with certain foods, these approaches do not adequately address the need for low cost, reliable approach for expanding amaranth and grain half products.
Therefore, it is an object of the present invention to provide an efficient means for a large scale production of popped amaranth and grain half products;
another object is to provide a means of expanding amaranth and half products of certain grains in a manner which results in a more nutritious food product;
yet another object is to provide an improved process for popping raw, wholeseed amaranth, resulting in a more consistent product available at lower cost.